Circuit protector



J. C. ELLIS ET AL CIRCUIT PROTECTOR March 29, 1960 Filed Jan. 16, 1958 5 Sheets-Sheet 1 l \INVENTORS,

J0/l/V 6'. ELL/S PORTER HOAGLAND, J19.

LEW/S J- WOODWARD March 29, 1960 J. c. ELLIS ETAL 2,930,937

cmcun' PROTECTOR Filed Jan. 16, 1958 5 Sheets-Sheet 2 LEWIS J- WOQD WARD ATTORNEY March 29, 1960 J. c. ELLIS ET AL CIRCUIT PROTECTOR Filed Jan. 16, 1958 3 Sheets-Sheet 3 INVENTORS, 1 JOHN (1 ELL IS TER HOA6LAND, JR.

IS J1 WDDDWARD WMJM ATTORNEY United States Patent O CIRCUIT PROTECTOR Application January 16, 1958, Serial No. 709,342

11 Claims. (Cl. 317-9) This invention relates to a circuit protector and, more particularly to a circuit protector for use in combination with electronic data processing equipment such 'as computers or the like.

Existing electronic data processing equipment consists of a great number of component sections, each connected to the complete system through circuit protecting fuses. The owner of such a system may lease its operation at up to $1,000.00 an hour. If one of the sections becomes inoperative by virtue of a defect causing the fuse to blow, the system is put out of operation until the fault can be located and corrected.

In order to overcome the disadvantages of the present arrangement utilizing fuses, the present invention has been developed. In essence, the invention consists of a thermal overload circuit breaker of such compact design that hundreds can be used in a system without adding too greatly to the overall dimension of the system.

In order to augment the usefulness of the circuit protector, it is provided with two sets of auxiliary contacts which are operated substantially simultaneously with the main contact. One set of auxiliary contacts are provided to interrupt the main circuit to the system including the time clock, the importance of which will be developed below. The other set of contacts is connected to an alarm signal light which will indicate to the operator the plaitiicular section of the system which has become disa le Another feature of the invention resides in the resetting arrangement. First, the reset button is provided with a long stroke upon tripping so as to expose a substantial portion of the reset button, normally obscured, the exposed portion being a different color from the remainder of the button so that the tripped circuit protector can readily be located. Additionally, there is an arrangement which cooperates with the reset button which will prevent the closing of the main contacts when the reset button is held in a depressed position but which will not interfere with the operation of the auxiliary contacts.

It is an object of the invention to provide a circuit protector for an electronic data processing system in which auxiliary contacts are provided to interrupt the main circuit of the system and to operate a signal light showing the location of the fault when the circuit protector is tripped.

It is another object of the invention to provide a circuit protector in which the main contacts cannot be reset until the reset button is depressed and subsequently released, provision having been made for the protector to trip during the reset operation at the point of load contact closure, if an overload condition still exists during the reset operation. This makes it impossible to hold the contacts closed under any condition, including gradual release of the reset button.

It is another object of the invention to provide a circuit protector having auxiliary contacts in which the auxiliary contacts will assume a reset position even mon auxiliary line connection 40.

though the main contacts are held out of engagement by the depressed reset button.

It is another object of the invention to provide a circuit protector in which the reset button has a long stroke so as to provide indicia through which the tripped circuit breaker can be located.

These and other objects of the invention will become more readily apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a cross sectional view taken along lines 1-1 of Fig. 2;

Fig. 2 is a cross sectional view taken along lines 22 of Fig. 1;

Fig. 3 is a cross sectional view taken along lines 33 of Fig. 1;

Fig. 4 is an end elevational' view of the invention; and

Fig. 5 is a circuit diagram of the invention.

The circuit protector consists of a housing 10 mounted on a panel 12 through which a reset button 14 and a manual stop plunger 16 project. Two main contacts 18 and 20 are fixed in the housing 10 and are normally bridged by a slideable contact 22 mounted between a block 24 and a contact spring insulator 26. The main contacts are connected into the circuit by terminal lugs 19 and 21. A contact spring 28 urges the movable contact 22 into engagement with the fixed contacts 18 and 20. The spring 28 also engages a slideably mounted auxiliary contact spring insulator 30 which bears against a contact leaf 32 having a contact leaf button 34 at the end thereof. The button 34 is movable between a normally open auxiliary contact 36 and a normally closed auxiliary contact 38 to connect these contacts to a com- The insulators 26 and 30 are slideable in channel 42 in contact operating slide or carrier 44. Block 24 is integral with contact carrier 44 and is in engagement with contact 22 as explained above. The contact carrier 44 is slideable between a tripped and operating position. A reset compression spring (Fig. l) 46 is compressed between a portion of the housing 10 at 48 and the contact carrier at 50 thereby normally urging the contact carrier toward a tripped position in which the contact carrier 44, acting through block 24, would carry contact 22 out of engagement with the fixed contacts. The contact carrier 44, when in tripped position, will shift auxiliary contact button 34 from auxiliary contact 38 to auxiliary contact 36.

The carrier 44 is normally prevented from movement to its tripped position by a latch lever 52 pivoted about a fulcrum 54. The latch lever 52 is held in its restraining position by a trigger catch 56 which engages a notch 58 in the latch lever 52. The trigger catch 56 is mounted on a trigger yoke 60 by rivets 62. A spring 64 coiled around the trigger yoke pivot 66 normally urges the trigger yoke and catch 56 into engagement with the notch 58. The catch 56 carries a trigger adjusting screw 68 which is engageable by a bi-metallic element 70 connected in series with the incoming line through terminals 72 and 74, terminal 74 being connected directly to fixed contact 18. The bi-metallic element 70 forms the primary overload trip mechanism and, upon overload, bears down against adjusting screw 68 to force catch 56 out of engagement with the latch 52 whereby latch 52 will permit the carrier 44 to slide into tripped position. A secondary tripping mechanism consists of the manual stop plunger 16 which carries a manual stop cam 76 engageable with a counterweight 78 at the end of the trigger yoke remote from the trigger catch 56. By press ing on the stop plunger 16, the cam 76 will engage counterweight 78 to rotate the yoke 60 counter-clockwise as viewed in Fig. 1, thereby tripping the circuit protector.

The reset mechanism consists of a slideable plunger 80 fixed to the button 14 at one endand carryinga reset-extension 82 at the other end. The extension '82 is recessed at 84 to receive a reset pin' 86 mounted on the latch 52 by retaining rings 88. Optionally,'a compression spring 90 can be mounted between the housing and the reset plunger urging the reset pin outwardly. Means are provided such as the projection 92 for maintaining the plunger in its innermost position until the mechanism is tripped. Upon tripping, the pin 86 drives the plunger out and the compression spring 90 continues the outward movement of the plunger beyond the position to which the pin 86 drives it so as to permit the exposure ofa fgreater portion of button'14 than wouldnormally. beprovided by the movement of pin 86 on tripping.

In order to prevent the maincontacts from being held closed by the operator holding the reset button in, a safety mechanism'operable by .the reset button is-provided. It consists of a spring arm 94 mounted on a spring pivot 96 at one end and lodged in a hole 98 ina stop plug 100. The stop plug 100 is slideable in block 24 and-engages the moveable contact 22 at 104 (Fig. 3).

It can be seen from Fig. 1 that pressure on the reset button 14 will causecontact carrier 44 to move toward operating position due to the clockwise rotation of latch .52 by the reset plunger acting on pin 86. However, if the reset button is pushed inwardly, the spring arm 94, engaged by the reset plunger 80 at 106, drives the plug 100 against the movable contact 22 to hold the movable -contact 22 out of engagement with the fixed contacts 18 .and 20 until pressure on the reset button'14 is released.

Thus, it is impossible for an operator tomaintain afaulty circuit energized by holding the reset button, and impossible to maintain a faulty circuit at instant of contact closure upon release of reset button.

The manner in which the circuit protector is applied to a data processing system is illustrated diagrammatically in Fig. 5. The main circuit consists of the incoming line 110 in series with the bi-metallic element 70, the bimetallic element 70 being connected to contact 18. Movable contact 22 connects fixed contact 18 to fixed contact'20, thereby connecting the line to a data handling section 112.

The auxiliary circuit includes auxiliary line 40'connected to contact leaf 32 which is movable between contact 36 and contact 38. Contact 36 connects the line to a warning signal indicating fault in the particular data handling section 112. Contact 38 connects the line 40 to suitable relays, not shown, to cause the energization of the main data handling circuit 114 and its associated time clock 116. The mechanical connection between main "contact 22 and contact leaf 32, described above, is illus- 'reset button is held in,.t-he faulty circuit will not be energized, but the fact that the reset button has been held in is detectable because of the movement of the timeclock being recorded.

In a general manner, while there has been disclosed in the above description, what is deemed to be the most practical and efficient embodiment of the invention, it should be well understood that the invention is not limited to such embodiment as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle ofthe present invention. as comprehended within. the scope of the accompanying claims.

What is claimed is:

1. A circuit protector comprising, a housing, at least one contact fixed to said housing, a contact operating slide slidably mounted in said housing between an operating position and a tripped position, auxiliary contacts in said housing and operable by said slide, at least one movable contact slidably mounted on. said slide for engagement with said fixed contact when said slide is in operating position, spring means urging said movable contact toward said fixed contact, overload trip means for moving said slide and movable contact to tripped position, reset means movable by an operator for moving said slide to operating position and safety means connected to said reset means for holding said movable contact out of engagement with said fixed contact until said reset means is released by the operator.

2. A circuit protector comprising, a housing, at least one contact fixed to said housing, a contact operating .membermovably mounted in said housing between an operating position and a tripped position, auxiliary contacts in said housing and operable by said contact operating member, at least one movable contact movably mounted on said operating member for engagement with .said fixed contact when said operating member is in operating position, spring means urging said movable contact toward said fixed contact, overload trip means for moving said operating member to tripped position, reset means movable by an operator for moving said operating member to operating position and safety means connected to said reset means for holding said movable contact out of engagement with said fixed contact until said reset means is released by the operator.

.3. A circuit protector comprising, a housing, at least one contact fixed to said housing, a contact operating slide slidably mounted in said housing between an operating position and a tripped position, at least one movable contact slidably mounted on said slide for engagement with said fixed contact when said slide is in operating position, overload trip means for moving said slide to tripped position, a reset button operably movable in a direction opposite to the direction of movement of said slide toward operating position, means connecting said button to said slide to move said slide to operating position and safety means for forming a connection between said button and said movable contact for holding said movable contact out of engagement with said fixed contact until said reset means is released by the operator.

4. A circuit protector comprising, a, housing, at least one contact fixed to said housing, a contact operating slide slidably mounted in said housing between an operating position and a tripped position, at least one movable contact slidably mounted on said slide for engagement with said fixed contact when said slide is in operating position, overload trip means for moving said slide to tripped position, a lever pivoted to said housing and having one end engaging said slide, a reset push-button extending into said housing and engageable with the other end, said lever to return said slide to operating position after it has been tripped, and a safety member connecting said reset pushbutton and said movable contact for holding said movable contact out of engagement with said fixed contact when said push-button is depressed.

5. In a data handling system having a main circuit,

and a plurality of data handling sections each having a said main circuit when said line interrupting contacts are 'open.

6, In a, data handling system having a main circuit,

and a plurality of data handling sections each having a line side, a plurality of circuit protectors each having line interrupting contacts installed in the line side of said data handling sections, overload means for opening said contacts, reset means movable by an operator for closing said contacts, auxiliary contacts for causing the de-energization of said main circuit when said line interrupting contacts are open and for permitting energization of said main circuit when said line interrupting contacts are open, and means permitting said last mentioned operation of said auxiliary contacts upon movement of said reset means while restraining the closing of said line interrupting contacts until said reset means is released by the operator whereby said main circuit may be conditioned for the closing of said line interrupting contacts before closure of said line interrupting contacts.

7. In a data handling system having a main circuit, and a plurality of data handling sections each having a line side, a plurality of circuit protectors each having line interrupting contacts installed in the line side of said data handling sections, overload means for opening said contacts, reset means including a button depressible and releasable by an operator for closing said contacts, and auxiliary contacts for causing the de-energization of said main circuit when said line interrupting contacts are open and for permitting energization of said main circuit when said reset button is depressed, stop means engageable with said line interrupting contacts, means connecting said stop means to said reset means for holding said line interrupting contacts open when said reset button is depressed.

8. A circuit protector comprising, a housing, at least one contact fixed to said housing, at least one contact carrier slidably mounted in said housing for movement toward and away from said fixed contact, a spring urging said carrier away from said fixed contact, a second contact mounted on said carrier and engageable with said fixed contact, a latch lever pivoted in said housing, one end of said lever engaging said slide, a trigger pivoted in said housing and engageable with the other end of said latch lever to hold said slide in a position toward said fixed contact against the action of said spring, and a bimetal element mounted in said housing and cooperating with said trigger to move said trigger out of engagement with said latch lever upon predetermined'overload.

9. A circuit protector comprising, a housing, at least one contact fixed to said housing, a contact carrier slidably mounted in said housing for movement toward and away from said fixed contact, a spring urging said carrier away from said fixed contact, a second contact slidably mounted on said carrier and engageable with said fixed contact, a spring between said carrier and second contact urging said second contact toward said fixed contact, a latch lever pivoted in said housing, one end of said lever engaging said slide, a trigger pivoted in said housing and engageable with the other end of said latch lever to hold said slide in a position toward said fixed contact against the action of said spring, and a bi-metal element mounted in said housing and cooperating with said trigger to move said trigger out of engagement with said latch upon predetermined overload.

10. A circuit protector comprising, a housing, at least one contact fixed to said housing, a contact carrier slidably mounted in said housing for movement toward and away from said fixed contact, a spring urging said carrier away from said fixed contact, a second contact mounted on said carrier and engageable with said fixed contact, a latch lever pivoted in said housing, one end of said lever engaging said slide, a trigger pivoted in said housing and having one end engageable with the other end of said latch lever to hold said slide in a position toward said fixed contact against the action of said spring, a cam follower on the other end of said trigger, a trip member slidably mounted in said housing, and a cam on said trip member engageable with said cam follower to swing said trigger out of engagement with said latch lever when said trip member is operated.

11. A circuit protector comprising, a housing, at least one contact fixed to said housing, a'contact carrier slidably mounted in said housing for movement toward and away from said fixed contact, a spring urging said carrier away from said fixed contact, a second contact mounted on said carrier and engageable with said fixed contact, a latch lever pivoted in said housing, one end of said lever engaging said slide, a trigger pivoted in said housing and havingone end engageable with the other end of said latch lever to hold said slide in a position toward said fixed contact against the action of said spring, a roller on the other end of said trigger, a trip member slidably mounted in said housing and a cam on said trip member engageable with said trip roller to swing said trigger out of engagement with said latch lever when said trip member is operated, said roller counterbalancing said trigger to reduce the eifects of vibration on said trigger.

References Cited in the file of this patent UNITED STATES PATENTS 739,380 England Oct. 26, 1955 

